AMVidia 7990GTX HD
Make sure to Use 3 or 4 at the same time using crossli otherwise you won't even get that 2mil fps that every gamer KNOWS is the sweetspot where screen tearing makes everything crisp and clear.

I use a Nvidia GTX460 with a i7-920 intel cpu with 8 gigs of ram at 1920x1080. I have it set to the highest setting except on 2x on AA with no motion blur and multi-core rendering on. I never get crashes but I do get bouts of system lag where the gameplay will freeze upwards to 5-7 seconds before resuming and i'm usually dead.